Queries :: All Results Not Shown Due To Empty Fields

I have a query which is supposed to search for all engines with a power rating between a user-specified range ('Rated Power'). The results should state all of these engines along with a few more related details ('System_ID_No', 'Project No', 'Rated Speed', 'Other Ratings' and 'Cylinder Capacity') that are useful to know. However, the problem arises when these other fields are empty. If empty, the related engine results do not appear in the final results spreadsheet. How do I make sure they are included aswell?

SQL:

SELECT tblProjectOverview.System_ID_No, tblProjectOverview.[Project No], tblProjectOverview.Customer, tblEnginePerformance.[Rated Power], tblEnginePerformance.[Rated Speed], tblEnginePerformance.[Other Ratings], tblEngineDefinition.[Cylinder Capacity]
FROM (tblProjectOverview INNER JOIN tblEnginePerformance ON tblProjectOverview.[System_ID_No] = tblEnginePerformance.[Sytem_ID_No]) INNER JOIN tblEngineDefinition ON tblProjectOverview.System_ID_No = tblEngineDefinition.System_ID_No
WHERE (((tblEnginePerformance.[Rated Power]) Between [Enter minimum power rating (kW):] And [Enter maximum power rating (kW):]));